Trans fat switch-out has not caused sat fat surge: Study

Evidence has mounted over the past decade showing that artificial trans fats clog arteries and cause heart disease. On the back of growing concern, the Food and Drug Administration (FDA) issued a regulation that was implemented in 2006 requiring manufacturers to list trans fatty acids on the nutrition panel of foods, providing further motivation for manufacturers to cut trans fats from their products. But there were concerns that slashing trans fat content could lead to increased total levels of trans and saturated fats, potentially mitigating any health benefits.

However, in a review of 83 packaged foods that had been reformulated to cut trans fat content since 2007, the researchers found that nearly all of them had lower total levels of saturated and trans fat following reformulation.

Lead author Dariush Mozaffarian said: “This study should alleviate concerns that most food manufacturers and restaurants would simply switch to a shortening high in saturated fat when they reformulated their products without trans fat. In only a small handful of baked goods, more saturated fat was added than trans fat subtracted following reformulation. Still, because a gram of trans fat is more harmful than a gram of saturated fat, even those changes represented relative improvements.”​

He added that in the majority of products, trans fat was reduced or eliminated without corresponding increases in saturated fat. Overall content of both saturated and trans fat was reduced in 90 percent of supermarket products surveyed, by an average of 1.2 grams per serving, the researchers found. For restaurant foods, the change was even greater, with total saturated and trans fat content reduced in 96 percent of products, by an average of 3.9 grams per serving.

The research was carried out by Dariush Mozaffarian of Harvard Medical School and Harvard School of Public Health and Michael Jacobson and Julie Greenstein of the Center for Science in the Public Interest (CSPI).

Trans fat is considered to be the most harmful form of fat because it raises levels of LDL (low-density lipoprotein, or so-called ‘bad’) cholesterol, while lowering levels of HDL (high-density lipoprotein, or ‘good’) cholesterol. Saturated fat, on the other hand – although it raises ‘bad’ cholesterol – has also been shown to raise slightly ‘good’ cholesterol.

In response to the study, CSPI president Michael Jacobsen praised the food industry for its efforts.

He said: “This paper demonstrates that the US food industry has been generally responsible in replacing partially hydrogenated oils with more healthful oils.”​

Jacobson hailed the study as a significant step to pave the way for the FDA to eliminate trans fats in the form of partially hydrogenated oils from the food supply. “The agency could do that quite easily by stating that it no longer considers partially hydrogenated oil to be ‘generally recognized as safe,’ and give companies a year or two to switch to healthier oils,”​ he said.

Trans fat bans are already in place in parts of the United States that account for 20 percent of the population, including New York City, Philadelphia, and the State of California.